Targeted Therapy

Targeted therapy represents a revolutionary shift in cancer treatment by:
✔️ Focusing on specific molecular/genetic cancer drivers
✔️ Minimizing damage to healthy cells (unlike chemotherapy)
✔️ Offering personalized treatment based on tumor biomarkers
✔️ Often causing fewer and less severe side effects

How Targeted Therapy Works

Key Mechanisms of Action:

  1. Blocking Growth Signals

    • Inhibits receptors like EGFR, HER2 that promote cancer growth

  2. Preventing Angiogenesis

    • Drugs like bevacizumab stop tumor blood vessel formation

  3. Promoting Cell Death

    • Triggers apoptosis in cancer cells

  4. Disabling DNA Repair

    • PARP inhibitors exploit BRCA mutations (synthetic lethality)

Common Targets:

  • HER2 (breast/gastric cancers)

  • BRAF V600E (melanoma)

  • ALK/ROS1 (lung cancer)

  • CDK4/6 (hormone receptor+ breast cancer)

Major Classes of Targeted Drugs

1. Small Molecule Inhibitors

  • Oral medications (e.g., imatinib for CML)

  • Target proteins inside cancer cells

2. Monoclonal Antibodies

  • IV/injected biologics (e.g., trastuzumab for HER2+ cancer)

  • Bind to surface antigens

3. Other Targeted Agents

  • PARP inhibitors (olaparib)

  • Angiogenesis inhibitors (lenvatinib)

  • Immunoconjugates (antibody-drug combinations)

Diagnostic Testing for Targeted Therapy

Essential biomarker tests include:

  • Next-generation sequencing (NGS)

  • Immunohistochemistry (IHC)

  • Fluorescence in situ hybridization (FISH)

  • PD-L1 testing for immunotherapy combinations

Clinical Benefits & Limitations

Advantages:

✅ Higher response rates in biomarker-selected patients
✅ Often better tolerated than chemotherapy
✅ Can overcome treatment resistance when combined
✅ Enables maintenance therapy approaches

Challenges:

⚠️ Only works for cancers with actionable targets
⚠️ Can develop resistance over time
⚠️ Some targeted drugs have unique side effects
⚠️ High costs and accessibility issues

Combination Strategies

Modern oncology increasingly uses:

  • Targeted therapy + immunotherapy

  • Targeted therapy + chemotherapy

  • Dual targeted agent combinations

  • Sequential targeted therapies

Future Directions

Emerging developments include:
🔹 Fourth-generation TKIs for resistant mutations
🔹 Bispecific antibodies targeting multiple pathways
🔹 PROTAC degraders to eliminate target proteins
🔹 Liquid biopsy for real-time monitoring

Is Targeted Therapy Right for You?

Key considerations:

  • Tumor molecular profiling results

  • Previous treatment history

  • Overall health status

  • Mutation-specific clinical trials

Targeted therapy has transformed outcomes for many cancer types, with over 100 FDA-approved targeted drugs now available. Consult your oncologist to determine if your cancer has actionable targets for these precision treatments.

💡 Early molecular testing maximizes treatment options – ask about comprehensive genomic profiling at diagnosis.

Filters
1 Results
Helaleh Khoshbakht

Helaleh Khoshbakht

Radiation Oncologist

Dr. Helaleh Khoshbakht is a highly respected radiation oncologist in Tehran with extensive expertise in treating various cancers, including breast, […]

Iran, Tehran